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path: root/drivers/acpi/thermal.c
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Diffstat (limited to 'drivers/acpi/thermal.c')
-rw-r--r--drivers/acpi/thermal.c28
1 files changed, 18 insertions, 10 deletions
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index ad898e10c1a9..5f79b4451212 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -195,6 +195,7 @@ struct acpi_thermal {
struct acpi_thermal_trips trips;
struct acpi_handle_list devices;
struct timer_list timer;
+ struct mutex lock;
};
static const struct file_operations acpi_thermal_state_fops = {
@@ -711,6 +712,7 @@ static void acpi_thermal_check(void *data)
int result = 0;
struct acpi_thermal *tz = data;
unsigned long sleep_time = 0;
+ unsigned long timeout_jiffies = 0;
int i = 0;
struct acpi_thermal_state state;
@@ -720,11 +722,15 @@ static void acpi_thermal_check(void *data)
return;
}
+ /* Check if someone else is already running */
+ if (!mutex_trylock(&tz->lock))
+ return;
+
state = tz->state;
result = acpi_thermal_get_temperature(tz);
if (result)
- return;
+ goto unlock;
memset(&tz->state, 0, sizeof(tz->state));
@@ -787,10 +793,13 @@ static void acpi_thermal_check(void *data)
* a thermal event occurs). Note that _TSP and _TZD values are
* given in 1/10th seconds (we must covert to milliseconds).
*/
- if (tz->state.passive)
+ if (tz->state.passive) {
sleep_time = tz->trips.passive.tsp * 100;
- else if (tz->polling_frequency > 0)
+ timeout_jiffies = jiffies + (HZ * sleep_time) / 1000;
+ } else if (tz->polling_frequency > 0) {
sleep_time = tz->polling_frequency * 100;
+ timeout_jiffies = round_jiffies(jiffies + (HZ * sleep_time) / 1000);
+ }
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s: temperature[%lu] sleep[%lu]\n",
tz->name, tz->temperature, sleep_time));
@@ -804,17 +813,16 @@ static void acpi_thermal_check(void *data)
del_timer(&(tz->timer));
} else {
if (timer_pending(&(tz->timer)))
- mod_timer(&(tz->timer),
- jiffies + (HZ * sleep_time) / 1000);
+ mod_timer(&(tz->timer), timeout_jiffies);
else {
tz->timer.data = (unsigned long)tz;
tz->timer.function = acpi_thermal_run;
- tz->timer.expires = jiffies + (HZ * sleep_time) / 1000;
+ tz->timer.expires = timeout_jiffies;
add_timer(&(tz->timer));
}
}
-
- return;
+ unlock:
+ mutex_unlock(&tz->lock);
}
/* --------------------------------------------------------------------------
@@ -1251,7 +1259,7 @@ static int acpi_thermal_add(struct acpi_device *device)
strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
acpi_driver_data(device) = tz;
-
+ mutex_init(&tz->lock);
result = acpi_thermal_get_info(tz);
if (result)
goto end;
@@ -1321,7 +1329,7 @@ static int acpi_thermal_remove(struct acpi_device *device, int type)
}
acpi_thermal_remove_fs(device);
-
+ mutex_destroy(&tz->lock);
kfree(tz);
return 0;
}